This invention relates in general to kilns and, in particular, to a kiln floor system adapted to dump a load of grain supported thereon.
More specifically, but without restriction to the particular use which is shown and described, this invention relates to a fully automated malt house kiln floor which allows a loaded floor to be dumped efficiently and in a minimum of time. The kiln floor system herein disclosed is capable of being readily installed in existing kilns and is designed for sustained, trouble free operation.
It has long been a practice to dry grain within a kiln and subsequently dump the loaded floor for subsequent use of the material in the brewing process. The malt being processed within the malt house typically may pile two or three feet high over a kiln floor at a density of approximately 80 to 120 pounds per square foot. Because of the large quantity of material being dried on the kiln, the floor has conventionally comprised a number of pivotal panel sections that allow the grain to dump in a sequential basis and minimize the forces required in the discharge process. Such floor sections have in the past been manually operated by a crew who progress down the length of the floor and physically rotate each section until the floor is totally dumped. Not only is such manual operation of a kiln floor an arduous and unpleasant task because of the work exerted and unhealthy surrounding conditions, a manually operated kiln floor requires a relatively long period of labor to complete the dumping sequence.
In recent years, several automated kiln floors have been introduced into the industry to overcome the inherent problems associated with manual operation, even though large numbers of manually operated kiln floors still exist at the present time. An example of an automated malt house kiln floor is disclosed in the Ricklick Patent, U.S. Pat. No. 3,243,894 issued Apr. 5, 1966. Such automated floors known in the prior art suffer from numerous disadvantages to the extent that optimum performance and reliability have not been attained. For example, prior automated kiln floors have reduced the length of time required to dump the grain from the floor as compared to manual operation, but these systems still require a relatively long period of time to discharge the grain completely from the floor. The inefficiency of these automated systems, such as disclosed in the Ricklick patent, occurs because of the use of cumbersome and ill-designed mechanisms to accomplish the pivotal action of each floor segment in a sequential manner. Because of such deficiencies, the automated systems previously employed in the industry have required the uneconomical use of force applying devices capable of exerting large forces to accomplish unloading of the kiln floor.
The present automated kiln floors are also incapable of being readily installed within the malt house with accuracy and once installed, to operate with a minimum of maintenance. Other problems are associated with known automated floors in use in malt houses. The grain supported on a kiln floor is generally subjected to a mixing action by a turning machine which moves slowly along the length of the floor while the drying process is being performed. A turning machine is normally provided with two or more flanged wheels that operate on a wear bar, and a driving pinion meshes with gear racks to propel the turning machine relative to the floor. However, after operation of the turning machine over a period of time, the gear rack and pinion are subject to wear and misalignment. As a result, the turning machine often falls onto the kiln floor and causes damage to both the grain and the floor itself, which results in extensive down time and repair. Past systems do not provide adjustment of the gear rack on a periodical basis to insure proper alignment of the pinion and gear rack, and prevent the turning machine from jumping the rack and falling against the floor.
Known automated kiln floors suffer from other shortcomings which interfere with effective operation and maintenance. Normally, the pivotal floor sections are covered by sheets or trays of metal attached to the frame structure of the floor. Conventionally, such trays include a leading and trailing portion that interconnect with an adjacent sheet to prevent the leakage of grain between the adjoining sections. In prior art devices, the edge portions of the sheet are a single layer of material and are attached to the framing members by means of rivets, screws or other attachment techniques. Fasteners in the form of rivets and the like are subject to popping loose under sustained use of the floor. Loose rivets and screws can fall into the grain and subsequently damage other machinery used in the brewing process. Such a problem in the food industry has required the government agencies to require fasteners to be magnetic so they can be detected and removed. In replacing a tray sheet, all fasteners must also be removed in order to repair and replace the trays. The necessity to remove each fastener during replacement of the sheets greatly complicates such expensive repair efforts.
In addition to the foregoing problems which have been recognized in the industry, the existence of a large number of manually operated kiln floors in use or, in some cases, inefficient automated systems, make it desirable that such floors be replaced at a minimum of cost and installation time with highly effective systems, such as provided by the invention of the application. This is particularly true at the present time due to energy considerations and government regulations.
Up to the advent of OSHA, EPA and FDA into the malting process and Brewery Industry, and the accelerated cost of fuel which is used to dry the barley malt, the maltsters did not recycle the spent hot kiln air but rather exhausted it out into the atmosphere. The above factors have required the maltsters to recycle the warm spent kiln air through heat exchangers so as to preheat incoming cold air and subsequently blend fresh heated air with recycled warm air. The spent kiln air during the tray dumping cycle is heavily laden with malt dust and is very injurious to the health of workers required to be in the dusty atmosphere. The exhaust fans are required to operate during the dumping cycle thereby forcing the dust laden air through the heat exchangers reducing their efficiency and requiring frequent cleaning. An alternate practice by some malsters is to by-pass the heat exchangers during the dumping cycle and exhaust the warm dust laden air directly out into the atmosphere. With the introduction of the fully automatic dumping kiln floor with remotely located controls as covered by the invention, the fans can be turned off or air flow greatly reduced as no personnel are required in the dusty atmosphere, such that the dust is not thrown into the heat exchangers, or into general plant area, or into the atmosphere, thereby improving health conditions, and reducing cleanup and fuel costs. In addition to the above advantages, the high efficiency of operation due to the present invention enables a complete floor to be dumped in eight minutes and fully reset in two minutes reducing the time and exposure cycle more than three or four times required by prior methods, including the system disclosed in the Ricklick patent, U.S. Pat. No. 3,242,894.
In the past, the installation of a fully automated system to replace an old manual arrangement requires significant structural alteration of the existing malt house, and the use of expensive components and labor to make the conversion. Known conversion techniques to update the equipment within a malt house have heretofore not provided suitable means by which such changes can be made efficiently and economically without, in effect, rebuilding the walls of the structure in order to support the components of the newly installed floor.